Remove obsolete Group tag

References: https://fedoraproject.org/wiki/Changes/Remove_Group_Tag

libdmtx.spec

@@ -3,7 +3,6 @@ Version:        0.7.5
 Release:        2%{?dist}
 Summary:        Library for working with Data Matrix 2D bar-codes
 
-Group:          System Environment/Libraries
 License:        BSD
 # http://www.libdmtx.org/ doesn't work any more
 # outdated info is still at http://libdmtx.sourceforge.net/
@@ -40,7 +39,6 @@ the LGPLv2 and can be used freely under these terms.
 
 %package        devel
 Summary:        Development files for %{name}
-Group:          Development/Libraries
 Requires:       %{name} = %{version}-%{release}
 
 %description    devel